code: def demo_plot_roi(**kwargs):
      """Demo plotting an ROI."""
      data = np.zeros((91, 109, 91))
      # Color a asymmetric rectangle around Broca area.
      x, y, z = -52, 10, 22
      x_map, y_map, z_map = coord_transform(
          x, y, z, np.linalg.inv(_affine_mni())
      )
      data[
          int(x_map) - 5 : int(x_map) + 5,
          int(y_map) - 3 : int(y_map) + 3,
          int(z_map) - 10 : int(z_map) + 10,
      ] = 1
      img = Nifti1Image(data, _affine_mni())
      return plot_roi(img, title="Broca's area", **kwargs)
  
file_path: nilearn/nilearn/plotting/tests/test_img_plotting/test_plot_roi.py
imports: import matplotlib.pyplot
  import numpy
  import pytest
  from nibabel import Nifti1Image
  from nilearn.conftest import _affine_mni
  from nilearn.image.resampling import coord_transform
  from nilearn.plotting import plot_roi
label_desc: Use image node_id 1 for calling a global function with example usage: demo_plot_roi() and returns: plot_roi